Given the number of electrically operated devices and the increasing networking of devices for data exchange, there is an increase in the number of necessary lines for transmitting electric power and electric and optical signals. This is particularly true, as well, for medical treatment facilities, in which moreover compressed air, water or other fluids are transmitted. The result, referred to colloquially as “cable salad,” is devoid of aesthetic value, makes maintenance difficult, and poses a risk of accidents and of damage to power lines by persons treading on them.
Patent DE 20 2007 016 599 U1 describes a cable winding device in which a main cable is wound about the upper part of a winding coil and a complementary cable of equal length is wound about the lower part of the winding coil.
In DE 31 28 545 A1, a cable roll-up device is described in which a dividing wall divides up a winding cylinder into a first part with a first, larger diameter and a second part with a second, smaller diameter. A cable that is to be wound up enters through a corresponding recess in the dividing wall between the first and the second parts of the winding cylinder. In wound-up condition, a few loose rounds of a non-extensible part of the cable are situated on the second part of the winding cylinder and several mutually contiguous rounds on the first part of the wind-up cylinder. In unwound condition, the first part of the winding cylinder is empty and the non-extensible part of the cable in the second part of the winding cylinder is wound up in a few tightly, mutually contiguous rounds.
In DE 20 2007 006 899 U1, a traction-operated cable winding device is described in which a portion of a cable, non-removable from the cable winding device, is wound loosely or tightly inside a cylindrical dividing wall. When a windable portion of the cable is wound up outside on the cylindrical dividing wall, the non-removable portion of the cable is wound closely. When the wound-up portion of the cable outside the cylindrical dividing wall is unwound or removed, the winding of the portion remaining in the cable winder is loosened.
DE 1 574 306 discloses a device for storing and operating electrical connecting cables, in which an electric contact to an end of a cable that rotates with a winding spool is produced by “electric grinder contact” between stationary contact sleeves and counter-grinding sleeves that rotate with the cable end.
A grinder contact, as described in DE 1 574 306 A, is unsatisfactory for many applications. In particular, a sufficiently reliable transmission of electric current or electric signals is possible for many applications only at considerable expense. Corresponding devices for transmitting optical signals or light power (for example, illuminating light for endoscopic applications) still require markedly greater expense and can only be satisfactory if, at the coupling point, the optical axis corresponds to the axis of rotation.
In addition, the devices described in DE 31 28 545 A1 and a few other cited publications comprise a series of disadvantages. In particular, an overall comparatively large conduit length is required because part of the conduit always remains in the cable roll-up device. The movements of this portion inside the cable roll-up device can be predetermined, at least to some extent, and constitute a source of malfunctions.